Parasitoid wasps lay their eggs in insect hosts, which they need to find in complex and dynamic natural environments. Through learning they can gather information on local conditions, such as the plant species on which hosts occur, and they can subsequently adapt their foraging behaviour according to this learned information to improve their host searching efficiency. This obtained information may, however, not always correctly predict host presence on these plants and may cause them to find unsuitable host species, i.e. non-hosts. In this thesis project, we studied how such unreliable information shaped the foraging behaviour of the parasitoid Cotesia glomerata. Through the development of advanced observation set-ups and methods, to track individually foraging parasitoid in the laboratory and the field, this thesis provides new insights on the effect of information-reliability on parasitoid foraging behaviour. This knowledge may be beneficial for the improvement of foraging models and biological control methods.